There are 2 possibilities that have different solutions.
1. The .,mdb or .mde file(s) is/are damaged. Then - if you can't open it for 'compact and repair' - go back to your latest backup.
2. The .,mdb or .mde file(s) is/are OK, but something is wrong with your Access installation or PC. Then try a repair of MS Access from Control Panel, a clean reinstall of MS Access or a reinstall of Windows and MS Access.
Since you don't tell the exact message it's impossible to say which of the 2 is more likely. So make a backup copy of the database as it is now, and start experimenting with first another database and then MS Access on another PC to find out more.
Hi all. Can anybody help me? Yesterday I work with my access file with necessary data for my work and today I can’t open it. I got a message with critical error. Maybe it is connected with some kind of virus, I don’t know. The version of Microsoft Office is 2003. Windows 7. Thank you!